1. Field of the Invention
This invention relates to the field of devices for chocking motor vehicles and is particularly directed towards those type chocking devices which are fixably attached to the apron of a loading dock, i.e., as opposed to the numerous other type devices which are a permanent fixture attached to the vehicle.
2. Description of the Prior Art
Loading and unloading of truck-like vehicles at a typical loading dock have resulted in numerous accidents which may be attributed to the truck driver prematurely pulling the vehicle away from the loading dock, i.e., prior to the actual completion of the loading and/or unloading operation. In other words, the loading and unloading is usually facilitated with the use of a typical fork lift which travels between the truck away from the loading dock without the fork operator being forewarned subjects the fork lift operator to the hazard of causing the fork lift to fall several feet from the loading dock or from the truck bed. This type accident might appear as a very remote possibility, however, it has been rather prevalent in this industry.
Indeed, this type accident has been so prevalent that the Occupational Safety and Health Administration (OSHA) now requires that the truck-like vehicles, i.e., typical straight truck chasis or semi-trailer and tractor rigs and the like, have wheel chocks placed in front of the rear wheels prior to the commencement of any loading and/or unloading operations.
Obviously, the task of manually placing and removing these wheel chocks has, to say the least, not been totally satisfactory. In fact, one attempt directed toward solving the problem has been to modify each vehicle with a wheel blocking system and the like. Each of the following U.S. patents is directed toward such vehicle modification: U.S. Pat. No. 2,483,048 granted to Hergner; U.S. Pat. No. 3,086,619 granted to Grotz; U.S. Pat. No. 3,321,046 granted to Cooper; U.S. Pat. No. 3,547,228 granted to Wiley; U.S. Pat. No. 3,625,313 granted to Lowrie; and U.S. Pat. No. 3,722,631 also granted to Lowrie.
It will be appreciated by those skilled in the art that merely modifying the vehicle so as to enable the truck driver to operate the chocking system at his will and pleasure, does not eliminate the aspect of human error from the problem, i.e., accidents still prevail simply because the truck driver is able to move his truck away from the loading dock at his will and pleasure or prematurely without regard for the forklift operator.
In addition to the above mentioned patents, the applicant is familiar with the following three United States patents which pertain to other type vehicle immoblizing devices: Patent No. 3,149,583 granted to Morrill; Patent No. 3,623,688 granted to Ansund; and Patent No. 2,661,505 granted to Dilione. None of the heretofore mentioned patents disclose or suggest applicant's device.
Another concept directed toward solving the above mentioned problem includes power operated wheel block structure permanently attached to the apron of the loading dock. The applicant is familiar with one such system patented in the United States under U.S. Pat. No. 3,305,049 granted to Willey. Obviously, this approach to the problem offers certain advantages over modifying each vehicle. However, the problem still prevails in that the truck driver can inadvertently remove the wheel blocks prematurely or while the loading/unloading operation is still in progress. It should also be mentioned that the Willey '049 patent does not disclose or suggest applicant's device.
Indeed, none of the above mentioned patents includes structure which provides any assurance that the vehicle must, in fact, be chocked prior to commencement of the loading/unloading operation. In addition, even though the vehicle has been properly chocked prior to commencement of the loading/unloading operation, the likelihood of premature removal of the wheel chocks remains a strong possibility and hazard.
It is significant to note that, almost without exception, typical trucking dock installations are now equipped with a remotely controlled dockboard means which normally may be selectively moved between: (1) an operating position in which the floor of the elevated dock structure is bridged with the floor of the truck-like vehicle as it is parked on the apron for facilitating the travel of fork lifts and the like between the floor of the truck and the loading dock, and (2) a stowed position in which use of the dockboard means is interrupted. It will be appreciated by those skilled in the art that there are numerous different remotely controlled dockboard means. One such dockboard is disclosed in a U.S. Pat. No. 4,091,488 granted to Artzberger on May 30, 1978 and assigned to Kelly Company, Incorporated, Milwaukee, Wisconsin. The Kelly Co., Inc. and their various dockboard systems are well known to those skilled in the art. Therefore, no attempt will herein be made to fully disclose a dockboard system even though the present invention is closely related thereto, i.e., at least one embodiment of the present invention is in combination with a typical dockboard system. Accordingly, while it is believed that a brief description of a dockboard system will suffice for present purposes, reference should be made to the Artzberger '488 patent and others assigned to the Kelly Co., Inc. for a more detailed description of the character and structure of dockboard systems.